Rotor for hammer mills



Aug. 8, 1950 M. N. DRESSEL ROTOR FOR HAMMER MILLS 2 Sheets-Sheet 1 Inuenlor Filed June 5, 1946 Aug. 8, 1950 M'. N. DRESSEL ROTOR FOR HAMMERMILLS 2 Sheets-Sheet 2 Filed June 5, 1946 I u ventor Merle M fifessel,

Patented Aug. 8, 1950 7' lVjIerle N; ll Jressel, Cloud,- Minn assignorof k v cneyhalftoplarence; A. Trossen, St., Cloud,

This invention relates a; hammermilland more particularly to an improvedhammer mill of the type disclosed in my prior patent, No. 2,013,378,issued September "3,v 1935.

. The primary object of the invention is to pulverize'and reducematerial toQa desired fine,- ness.

Another object istb entitle the same device to bev employed forproducing various grain sizes .0f the pulverized materiaL; ay;

The above and other objects may be:attained by employing this inventionwhich embodies :among its features a vertically disposed convolute drumhaving a peripheraldischarge opening.. and an inlet opening in at least.one side wallnear the center thereof, a shaft nounted in saidvdrum torotate about a horizontal axis,a circular cylinidrical screen removablymounted in said; drum :iccncentric with the shaft, arms radiating; fromithe shaft in the screen and blades pivotfidto the armsfor cooperationwith-the screen in :pulver-izing material introduced; into $11 3 ildrumt ou h h i et p nin hsaid s ,r so 1 operating with the drum casing increating an air-blast through the discharge opening whereby thepulverized material will be ejected from the drum.

Other features include providing the drum with an air intake opening inthe side opposite the inlet opening through which the material isintroduced, means to regulate the amount of air entering the drumthrough the air intake opening, and a hopper to feed the material to thedrum through the inlet opening.

In the drawings:

Figure 1 is a side view of a hammer mill em bodying the features of thisinvention,

Figure 2 is a vertical sectional view taken substantially along the line2--2 of Figure 1,

Figure 3 is a vertical sectional view taken substantially along the line33 of Figure 2,

Figure 4 is an enlarged fragmentary sectional view taken substantiallyalong the line 4-4 of Figure 2, and

Figure 5 is a fragmentary elevational view, parts being shown invertical section, illustrating the relation between the pivoted andfixed blades.

Referring to the drawings in detail, my improved hammer mill designatedgenerally IIl comprises substantially square side plates II and I2 heldin spaced parallel relation by a convolute wall I3 having a peripheraldischarge opening communicating with a discharge duct I4 arrangedbetween the walls II and I2, and extending upwardly as illustrated inFigure 3. The side Fwall II is provided 1w h a journal bearing IS .whichaligns with a journal bearing I6 carried by the; side wall I2 and in.vvhichthefshaft to be more fully hereinafter, describedis mountedto'rotate. Formed in theside wall II adjacent the journal ,bearingjIE isan inlet opening I; l

through which;;the material ;tobe pulverized is introduced, into the,interior of the drum 10, A

valved ina manner to be'more fully hereinafter explained. b I 5 g m-Attachedito the Wall 1.2 above the ope i is an angle bracket 20supporting avvertically .mova ble,;; externally screw 1 threaded;jqshaft" 2 I carrying a nut 22 by means of which the shaft :2] maybe-adjusted vertically. I Attachedtothe lower end of the shaft and:riding in suitable guides 23 carried anther-wall I2 adjacent oppo- .siteends of the opening 1 His a plate 24 by means .of which the area of theopening ;-I 9 may be lv if i .1. "-31 Mountedin the bearings I5 and I 6to rotate about a horizontal axis is a drive shaft 25 which is formedbetween the bearings I5 and It with an area 26 of hexagonal crosssection. Driven onto opposite ends of the hexagonal area 26 are hubs 21carrying adjacent their outer ends flanges 28, and fixed to the hubs 2'!and flanges 28 are radial arms 29 carrying adjacent their outer endspivots 30. Pivotally supported on the pivots 30 are blades 3| which areadapted to cooperate with the screen to be more fully hereinafterdescribed in reducing and pulverizing the material introduced into theinterior of the drum. Fixed between each pair of arms 29 is a radialblade 32 and carried on the outer side of each arm 29 is a radiallyextending knife 33 having an outwardly disposed inclined sharpened edge34. These knives serve to cut fibrous material introduced into thedevice and prevent its collection between the arms 29 and the walls IIand I2, while the radial blades 32 not only serve to create a blast ofair through the device but also to prevent the lodging of fibrousmaterial in the space between the arms 29 and the consequent clogging ofthe machine.

The screen previously referred to is designated generally 35 andcomprises a cylindrical foraminous member 36 concentrically disposedwith relation to the shaft 25 within the drum I0, and in close proximityto the extreme outer edges of the blades 3|. Carried by the foraminousbody removably secured to the wall l2 iby spaced.

screws 39.

In operation, it will be "understood that the material is introducedinto the drum from the hopper [8 through the passage or inlet opening l1and the shaft 25 rotated in its bearingszll5 and I6. The centrifugalforce created by the rotation of the arms 29 and blades 3| will causethe blades to tend to move against the material into a radial position,thus forcibly driving the material against the screen 35 80 as to hammerthe material until it attains a fineness which will permit at to passthrough the foraminous wall 33 and into the passage formed between theconvo'lute wall IQ of the drum and the screen. The rapid rotation of theblades 3| alsoserves to :create a vgiraft-of air through the opening I 9to the interi'or-of the drum and thence'out through the dischargepassage l4. Ihe blast of air thus created is ladened with the pulverizedmaterial which writers the passage through the screen -35 and in thismanner the pulverized material is also "discharged through the passage Mfrom whence it maybe delivered for storage or packaging and shipment.

From the foregoing it will be obvious that I'not only utilize thecentrifugal'force of the blades -3l to pulverize the material introducedinto the drum, but also these blades serve in the capacity of theimpellers of-a blower so as to pick up the pulverized material anddischarge it from the device. Obviously screens 35 of varying degrees offineness may be employed and by the simple expedient of removing thebolts from the ears 3! it is apparent that the screen readily may bechanged.

While in the foregoing there has been shown and described the preferredembodiment of this invention it is to be understood that minor changesin the details of construction, combination, and arrangement tof' partsmay ,be resorted to without departing from the spirit and'scope of theinvention as claimed.

I claim:

:In a hammer mill, a rotor comprising a 1'0- tatable shaft,circumferentially spaced pairs of longitudinally spaced arms on saidshaft, blades 'pivotally connected to each pair of arms, laterallyextending blades carried by each of said arms disposed :beneath saidpivoted blades and inclined outwardly and radially from the axis ofrotation, and radial blades fixedly secured to and disposed between eachpair of arms beneath said pivoted blades.

N. DRESSER REFERENCES CITED The, following references are of record in,.the file of this patent:

HNI'BED STA E TE Number Name Date 144,330 Gardner Nov. 4,187.8 6'795046De --Camp- July 23 1 901 557,969 S'choe'llhorn Apr. 19, 1904 "845}1'71"Gardner 26;, 11907 908301 .Ponsar Jan. 5, -l 909 1,572,722 JacobsonFeb. 9, 1926 '-1 ,647,'1-83" *Leggemann Nov. 1, 1-927 1,758,702 JacobsonMay 13, 1930 ,8012842 Briggs Apr. 21, 1951 "1,861,779 I 'Born'hauserJune I l- 932 1,934,180 Fischer Nov. 7', E933 2,026,426 Matejci k Dec.-3-1, I935 2 ,"289197 Miller Apr. 22, 1941 22415667 lvlari'lcoif' May13;, 1 941

